Mycophenolate mofetil in the treatment of focal segmental glomerulosclerosis

Primary focal segmental glomerulosclerosis (FSGS) is a common cause of end-stage renal disease in both children and adults. Our current treatments are suboptimal, and a significant percentage of cases are resistant to current therapy.

We performed an open-label, 6-month trial of the new immunosuppressive agent mycophenolate mofetil (MMF) in 18 biopsy-proven patients resistant to a course of corticosteroids therapy. Seventy-five percent had also failed to respond to a cytotoxic agent and/or a calcineurin inhibitor.

A substantial improvement in proteinuria was seen in 44% (8/18) of the patients by 6 months. This was sustained for up to 1 year post treatment in 50% (4/8) of this group. No patient had a complete remission. No deterioration in renal function was observed in any patient over the treatment period, but 3 progressed to chronic kidney failure during follow-up. Adverse effects were mild. Only 1 patient required a dose reduction due to an intercurrent infection.

MMF appears safe to use in this group of patients and did lower proteinuria in 44% of this cohort resistant to other forms of treatment. Relapses were common, suggesting more prolonged or combination therapy may be required. More rigorous trials utilizing this medication should be considered to further assess the risk-benefit ratio of treatment with MMF in patients with FSGS.